Bernie Sanders said Monday that the Democratic National Convention in Philadelphia could get “messy” in July as he tries to advance a more progressive vision of the party’s platform.

The Vermont senator declared that “democracy is not always nice and quiet and gentle” during an interview with The Associated Press, as diehard supporters planned to shake up the convention and shape the party’s future.

Sanders said he will “condemn any and all forms of violence” but is expecting to bring political novices into the convention process and is hoping they will be accepted by the establishment.

“I think if they make the right choice and open the doors to working-class people and young people and create the kind of dynamism that the Democratic Party needs, it’s going to be messy,” he said.

Sanders is vying for support ahead of California’s June 7 primary, a day that also includes contests in New Jersey and four other states.

The senator spoke after the Democratic National Committee announced a 15-member platform-drafting committee.

Sanders will pick five of the members, while Clinton picks six and the DNC chooses the remaining four.

He said the drafting of the platform would be an “excellent time to educate the American people. There are two sides to every issue and I’m sure that Secretary Clinton will have very vigorous proponents of her point of view, as we will have.”